Flying IFR with Garmins

"Michael 182" wrote in message news:li4Ac.64896$Sw.58611@attbi_s51...
"Andrew Sarangan" wrote in message
. 158...
(Robert M. Gary) wrote in
om:

I just recently decided to buy our first Garmin GPS (296). I had not
in the past because they were so far behind on providing terrain. They
fixed that with the 296. However, the one outstanding item missing on
the 296 are airways. On my Skymap IIIc I can easily fly an airway by
putting the white course line on the pink airway line. Airways are
pretty common in the West where airways provide routes around
restricted airspace and around busy areas (like LAX) so ATC often
gives you airways rather than a million vectors (our airways are not
straight, they turn like roads).

So how do you Garmin guys easily fly along an airway graphically?

-Robert

Why not use a VOR receiver for airway navigation? Using a GPS for airway
navigation kind of seems backwards.

Because you can enter a full flight plan and follow it, rather than fiddling
with the VOR receivers every 15 minutes.

Michael

And you don't have to try to figure out the correction angle while
trying to stay on the airway while you are getting bounced around in
the clouds in busy airspace. Also, you don't need to change the VOR
everytime the airway turns. You easily see that on a GPS.

"Robert M. Gary" wrote in message
om...

And you don't have to try to figure out the correction angle while
trying to stay on the airway while you are getting bounced around in
the clouds in busy airspace.

There's nothing to stop you using the VOR for course guidance but using the
GPS track readout to ensure that your track matches the VOR radial. Forgive
me if that's very obvious, but I'm always surprised at how many pilots don't
use that aspect of the GPS to take the hard work out of tracking
conventional navaids (particularly on the ILS).

Julian Scarfe

I agree that this is a great technique. In fact I never use NAV mode on
my autopilot, I just tweak the heading until the track matches what it
should
be (and keep an eye on it obviously). Much better than the autopilot
zigzagging its way down the airways.

John

"Julian Scarfe" wrote in message
news:yMbBc.15$9D3.5@newsfe6-win...
"Robert M. Gary" wrote in message
om...

And you don't have to try to figure out the correction angle while
trying to stay on the airway while you are getting bounced around in
the clouds in busy airspace.

There's nothing to stop you using the VOR for course guidance but using
the
GPS track readout to ensure that your track matches the VOR radial.
Forgive
me if that's very obvious, but I'm always surprised at how many pilots
don't
use that aspect of the GPS to take the hard work out of tracking
conventional navaids (particularly on the ILS).

Julian Scarfe

Sounds like you have a Cessna 300A.

Michael


"John Harper" wrote in message
news:1087790958.150362@sj-nntpcache-5...
I agree that this is a great technique. In fact I never use NAV mode on
my autopilot, I just tweak the heading until the track matches what it
should
be (and keep an eye on it obviously). Much better than the autopilot
zigzagging its way down the airways.

"John Harper" wrote in message
news:1087790958.150362@sj-nntpcache-5...
I agree that this is a great technique. In fact I never use NAV mode on
my autopilot, I just tweak the heading until the track matches what it
should
be (and keep an eye on it obviously). Much better than the autopilot
zigzagging its way down the airways.

"Michael 182" wrote in message
newsDtBc.126215$3x.55034@attbi_s54...
Sounds like you have a Cessna 300A.

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement. Then it makes largish corrections and ends up snaking its way
along the centerline, albeit with decreasing amplitude oscillations. And if
*all* you have is a CDI, that's probably the best you can do. But it's
hooked up to the GPS and so I would expect it to be able to turn directly to
a waypoint without the major heading excursions that scare the hell out of
ATC in a busy environment.

Julian Scarfe

On Mon, 21 Jun 2004 08:11:04 +0100, "Julian Scarfe"
wrote:

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement.

I have an STEC50 and a CNX80.

The CNX80 has airways, so regardless of how I am cleared, I track enroute
using GPS mode.

As recommended by STEC, I use the APR mode for tracking a GPS course.

My off-track distance does vary, but by usually less than 1000'. In
heading mode, I will eventually drift off that much, or more. The turns
are rarely more than five degrees, once centered.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Ron Rosenfeld" wrote in message
...

As recommended by STEC, I use the APR mode for tracking a GPS course.

That could get entertaining if you pick up a glide slope while
you're at altitude....

We have an STEC 60-2 in our Bonanza 36 with a Trimble Approach 2000 GPS and
a King HSI. After we had the autopilot tweaked for tracking a GPS course,
it's been very good tracking in NAV mode.

"Julian Scarfe" wrote in message
news:OKwBc.8$AX2.5@newsfe6-win...

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement. Then it makes largish corrections and ends up snaking its way
along the centerline, albeit with decreasing amplitude oscillations. And
if
*all* you have is a CDI, that's probably the best you can do. But it's
hooked up to the GPS and so I would expect it to be able to turn directly
to
a waypoint without the major heading excursions that scare the hell out of
ATC in a busy environment.

Julian Scarfe

"Michael 182" wrote in message
newsDtBc.126215$3x.55034@attbi_s54...
Sounds like you have a Cessna 300A.

A Century 31. It's a good autopilot and flies smoothly even with
a fair amount of turbulence, and holds altitude to within a few feet.
But its nav following isn't great. I think it could be fixed with
some tweaking, but I've given the avionics shop enough of
my money as it is, and it isn't a practical problem.

John


Michael


"John Harper" wrote in message
news:1087790958.150362@sj-nntpcache-5...
I agree that this is a great technique. In fact I never use NAV mode on
my autopilot, I just tweak the heading until the track matches what it
should
be (and keep an eye on it obviously). Much better than the autopilot
zigzagging its way down the airways.

How do you do that with the 296? How do you program in a radial to fly
to? I don't even see radials on the VORs when I look at it. I haven't
been able to find anything on this in the manual.

There's nothing to stop you using the VOR for course guidance but using the
GPS track readout to ensure that your track matches the VOR radial. Forgive
me if that's very obvious, but I'm always surprised at how many pilots don't
use that aspect of the GPS to take the hard work out of tracking
conventional navaids (particularly on the ILS).

Julian Scarfe